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Coupler
Couplers, also known as Couplings are mechanical assemblies that join railcars so to makeup a trains consist. The couplers, track gage, brakes, clearances, etc of a given railcar, are just some of many factors that determine compatibility with other pieces of rollingstock & a specific railway. An entire Coupler assembly typically includes various components; knuckle, head, shank, release, striker, yoke, follower, drawgear... RailCar couplers are very generally categorized as follows: * FullManual Couplers require a trainman to step between cars to manually couple+decouple mech +pneu +elec connections. * SemiAuto Couplers automaticly couple+decouple the mech connection, but require manual pneu +elec connections. * FullAuto Couplers automaticly couple+decouple all mech +pneu +elec connections. Link&Pin Couplers Link&Pin couplers are a FullManual design that originated on NAmerican railways in the early 1800s. They are cheap to make, functionally simple, yet very dangerous to use: a drawbar\buffer projecting away from the railcar frame allows access to a vertical pin that holds a link in place; the link extends out the end of the drawbar\buffer; as cars come together, the opposite pin is raised by one hand of the trainman while his other hand guides the link into the opposing drawbar\buffer, then the pin is lowered thru the common link, thus coupling the cars. Uncoupling is the reverse procedure & only slightly less dangerous for the trainman. As NorthAmerican railways expanded & became more interconnected, Link&Pin couplers became more problematic: injury & death to trainmen due to these couplers became common as RailCars became heavier; loose Pins & Links often were missing or the wrong size. Finally in 1893 the US Congress mandated a 10+Year transition, outlawing the Link&Pin, along with other lesser coupler types of that era, & required newly developed Janney couplers (per MasterCarBuilder\MCB standards) for NAmerican 4f708 1m435 Gage interchange. In the years since, Link&Pin couplers have been generally outlawed worldwide, now only seen on Preserved\Museum stock & isolated Colonial\Industry\Mine\Plantation stock. Link&Hook\UIC Couplers ThreeLink&Hook\UIC3 couplers are a FullManual design, AlsoKnownAs Loose couplers, that originated on railways of Britain in the early 1800s, & just recently have been removed from service with the retirement of LooseCoupled BritishRailways\BR Goods\Freight stock. ThreeLink couplers are cheap to make & functionally simple, yet dangerous to use. Stock fitted with this coupler have a drawhook connecting to internal draftgear, along with a pair of sprung buffers on each end of the car. A ThreeLink chain hangs from a Gedge\Notch in each hook shank; after 2 cars are pushed together, one of the two ThreeLink chains is lifted into the opposing hook. A shunting pole can be used to manipulate the chains, which is somewhat safer than being between the buffers. A disadvantage of this design is the resulting "loose" coupling, meaning several inches of slack is inherent, which must be taken up in tension as the consist accelerates & again compressed as the consist decelerates. This causes much wear & tear on each cars structure, draftgear, buffers & lading, thus as improved coupler designs became available, only slow Goods\Freight stock were allowed to use ThreeLink couplers. An advantage is less of the consists weight is on the locomotive as it accelerates, thus why this coupler remained is use so long. Legacy British ThreeLink couplers are compatible with legacy CloseLink couplers & standard BR\EU\UIC ScrewLink couplers. CloseLink&Hook\UICC couplers are a FullManual design, AlsoKnownAs Instanter couplers, & mechanical improvement over ThreeLink couplers; the center link is now replaced with a special triangular link, allowing 2 positions: LooseCoupled for shunting or CloseCoupled for mainline running. A shunting pole may be used to Connect\Disconnect\Adjust the links. ScrewLink&Hook\UICF\UICP couplers are a FullManual design & defacto standard in Britain +IreLand +Europe for both Goods\Freight & Passenger stock. The ScrewLink design is a mechanical improvement over both ThreeLink & CloseLink couplers; in essence it is a ThreeLink with an OpposingThread TurnBuckle replacing the center link. However this design is more dangerous as shunting poles can not be used, thus trainmen must go between cars +buffers to connect\disconnect this coupler. Standard BR\EU\UIC ScrewLink couplers are generally compatible with legacy British ThreeLink & CloseLink couplers. Janney\AAR Couplers Janney\AAR couplers, AlsoKnownAs APT\ARA\MCB\Knuckle couplers, are a SemiAuto design; mechanical mating +separation is automatic; any required PneumaticPipe+ElectricCable connection is seperate & manual. Inspired by the human hand, then patented 1873~1914 by E.Janney Of USVI, the design was steadily improved thru several decades by the McConway&TorleyCo, PennsylvaniaRailRoad\PRR, MasterCarBuilders\MCB, AmericanRailwayAssoc\ARA, AmericanAssocRailways\AAR & AmericanPublicTransportion\APT to become a practical reliable coupler, requiring little maintenance, durable in abusive service & extreme environments. : : AAR couplers operate much like Willison couplers, but with jointed\hinged nucks instead of interlocking heads. At least one nuck must be open to allow mating; as 2 cars come together, the nucks are pushed closed by the palm of the opposing coupler until latch pins hold the nucks locked. To decouple, cars are pushed together for slack, one pin is raised with a side lever allowing that nuck to open & the cars are free to part. An advantage over Willison couplers is AAR couplers intentionally have Nucks of lower strength than the Head or Shank, thus the Nuck acts as a ShearPin when overstressed & is readily replaced onsite by the train crew; a disadvantage is Willison couplers mate without concern for Nuck closed\open position. : : AARC\MCB5\Transition couplers were mandated by the US Congress in 1893, which forced replacing dangerous Link&Pin couplers on Freight stock & unreliable MillerHookPlatform couplers on Passenger stock, greatly reduced injuries & allowed efficient interchange of rollingstock amongst 4f708 1m435 StandardGage railroads across NAmerica. AARC\MCB5\Transition couplers have Contour#5, 9i25 LongHeads (measured MateLine~Horn), 9i TallNucks, mate to all other AAR\APT\ARA\MCB standard subtypes & connect to outlawed Link&Pin+MillerHookPlatform couplers when fitted with a SplitNuck. Upto 21i TallNucks were often used on Tram+Logging+Ferry stock to avoid decoupling on rough\uneven track. The NationalCo.Sharon (make.model) coupler was likely the most popular amongst a multitude of AARC\MCB5 1893~1914 designs & remains in use on Preserved\Museum stock as of this 2019 writing. : : AARC\UICD\DropHead couplers (make.model=BECo.DropHead) were first conceived ~1898 by N.Gresley of Britain & designed+produced by BuckEyeCo of USOh, specificly for Passenger TeakCorridor stock. They've since been produced at UK\EU foundries & also used on British +Irish PassengerMultiUnit +FreightUnit stock. AARC\UICD\DropHead couplers have Contour#5, 9i25 LongHeads, 9i TallNucks, mate to all other AAR\APT\ARA\MCB standard subtypes & pivot downward to reveal a BR\EU\UICD coupler hook for emergencies. : : AARD\ASF3\Alliance couplers (make.model=ASF.Model3\Alliance) were first designed ~1913 by R.Janney (son of E.Janney) & manufactured by AmericanSteelFoundries at USOh Alliance, in heated competition for the pending 1915 ARAD standard, but lost out to A.Bazeley+NaCo. R.Janney+ASF then defiantly marketed their Alliance outside of NAmerica as a LessCostly LiteDuty coupler. These couplers have improved Contour#10, though shorter\weaker 10i LongHeads compared to AAR\ARA standard 12i LongHeads, but remain compatible & mate to all other AAR\APT\ARA\MCB standard subtypes. As various steel foundries around the world (LAFHenricot, OMBES, Sable, TedRail, WCR, BradKen, RIS...) licensed +marketed +improved the design, AARD\ASF3\Alliance couplers & several resulting evolutions became common on Passenger +Freight stock of Australia +Brazil +Britain +Burma +China +Cuba +Dijaboti +Ecuador +Ethiopia +India +Indonesia +Japan +Korea +Malaysia +NewZ +Panama +Phillipines +Saudi +SAfrica +Taiwan +Tanzania +Thai +Vietnam +Zambia +Zimbabwe... : : AARD\ARAD\Bazeley couplers (make.model=NaCo.Bazeley), superceding AARC, became the AARD\ARAD standard in 1915 for both Freight & Passenger duty. AARD\ARAD couplers have improved Contour#10, stronger 12i LongHeads, 9i TallNucks & mate to all other AAR\APT\ARA\MCB standard subtypes. Optional 11i TallNucks were often used on Lokomotives fitted with AARD\ARAD couplers. : : AARE\ARAE\GeneralDuty couplers, superceding AARD +AARC, became the AARE\ARAE standard in 1932 for Routine Freight: BoxCars +CenterBeams +Hoppers +Flats +Gondolas +InterModals +AutoRacks +Reefers... AARE\ARAE couplers have improved Contour#10A, 12i LongHeads, stronger 11i TallNucks & mate to all other AAR\APT\ARA\MCB standard subtypes They are the most common of AAR\APT\ARA\MCB couplers. : : AARF\APTF\InterLock couplers, conceived in 1901 by E.Ramsay@PrattCoalCo of USAL, became the AARF standard in 1954 for HazmatTank+RotaryGondola Freight Wagons & later the APTF standard for DualService=Freight+Passenger Lokomotives. AARF\APTF couplers have Contour#10A with SlackPadding, 12i LongHeads, 11i TallNucks & mate to all other AAR\APT\ARA\MCB standard subtypes. They prevent decoupling\punctures in derailments, minimize slack, & allow RotaryDumping of Gondola Freight Wagons. : : AARH\APTH\TightLock couplers evolved from the 1908 VanDorn#20 on the Hudson&Manhattan, the 1909 VanDorn#31 on the Chicago&Southern & the 1915~1927 HType by E.Henricot of Etienne Belgiumused on NMBS\SNCB stock, which were efforts to improve upon MCB5+ARAD+Alliance couplers of that era. A further improved & noticably evolved design, first used 1928 in NAmerica on the NewYorkCentralRR, became the AARH\APTH standard in 1947 for Passenger Lokomotives+Wagons+MultiUnits. AARH\APTH couplers have Contour#10A with SlackPadding, 12i LongHeads, 11i TallNucks & mate to all other AAR\APT\ARA\MCB standard subtypes. They prevent decoupling\telescoping in derailments, minimize slack, & allow Pneumatic+Electric appliances that convert AARH couplers from SemiAuto to FullAuto operation. : AARD\UICS\SwingHead couplers, which pivot to a BR\EU\UICS coupler hook, are used on unitized Passenger +Freight stock of Britain +SriLanka. : AARE\UICI\SwingLink\CentreBuffer couplers, with pivoting BR\EU\UICI coupler links, are used on unitized Passenger +Freight stock of India +SriLanka. : Willison\CAK Couplers Willison\CAK couplers are a SemiAuto design originally patented 1913 by J.Willison@NationalCastingsCo\NaCo of USOh. First intended for abusive duty in extreme environments, the rugid Willison coupler has become a world standard for Farm\Plantation +Mine\Industrial +Colonial\NarrowGage railways, & are available in 050% +075% +Full sizes. Willison Couplers operate much like Janney Couplers, though with interlocking Heads instead of hinged Nucks. A Willison advantage compared to Janneys, is they mate without concern for Nuck closed\open position; a disadvantage is Willisons do not have breakaway Nucks & a broken Head\Shank is not easily repaired by TrainMen. After the original design was enlarged\improved by NaCo Of USOh & LAF Of France, combination Willison+Screw Couplers were used on 1932~1970 French\SNCF.141TC lokomotives & associated passenger cars serving Paris~Nord routes. After further testing\improvement, in 1935 Russia made the Willison\CA3 coupler standard for the entire RZD broadgage railway; this version has cast letters CA3 meaning CоветскихAвто3 in Russian or SA3 meaning SovietAuto3 in English, & is used across continental Russia +FinLand +Mongolia +Ukraine +Turkey +Iran... A newer CоветскихAвтоKuppling5\CAK5\CAKv version is used in Russ~Euro interchange, being compatible with both Russian\RZD CA3 & BR\EU\UIC Screw couplers. Scharfenberg Couplers Scharfenbergs are FullAuto couplers originating in 1903 designs by K.Scharfenberg of Konigsberg Germany. AlsoKnownAs SchaKu\Dellner\Voith couplers, Scharfenbergs have become the most common coupler worldwide to be used on unit passenger trains: DMUs +EMUs +Tram\LRVs... As two Scharfenberg couplers come together, brakepipes mate & cocks automaticly open, & rotating covers reveal electric contacts. To uncouple, a remote release is operated from the cab. Evolutions of the Scharfenberg, Shibata & Shinkansen couplers are standard on Japanese +Korean passenger stock. Relative higher cost\complexity, need for covers\heaters in dirty\winter service, & limited draft ratings, cause this coupler to be rarely used on freight\goods stock. Refs * RailCarCouplers At OBTS Wiki * RailCarCouplers At WikiVisually Category:Locomotive Parts Category:Steam Locomotive Principles Category:Diesel Locomotive Principles Category:Electric Train Principles Category:Encyclopedic articles